A blood pressure measuring system includes: a blood pressure monitor which is configured to invasively measure a blood pressure value of a subject a calibrating section which is configured to calibrate a measurement reference value of the blood pressure value an imaging section which is configured to acquire an image of the subject a heart position identifying section which is configured to identify a height position of a heart of the subject based on the image and a determining section which, based on the identified height position of the heart, is configured to determine whether a calibration of the measurement reference value is necessary or not.
